-- |
-- Module      :  Configuration.Dotenv.Types
-- Copyright   :  © 2015–2020 Stack Builders Inc.
-- License     :  MIT
--
-- Maintainer  :  Stack Builders <hackage@stackbuilders.com>
-- Stability   :  experimental
-- Portability :  portable
--
-- This module contains common functions to load and read dotenv files.
{-# LANGUAGE RecordWildCards #-}

module Configuration.Dotenv
  ( -- * Dotenv Load Functions
    load
  , loadFile
  , parseFile
  , onMissingFile
      -- * Dotenv Types
  , module Configuration.Dotenv.Types
  ) where

import           Configuration.Dotenv.Environment    (getEnvironment, lookupEnv,
                                                      setEnv)
import           Configuration.Dotenv.Parse          (configParser)
import           Configuration.Dotenv.ParsedVariable (interpolateParsedVariables)
import           Configuration.Dotenv.Types          (Config (..), defaultConfig)
import           Control.Monad.Trans                 (lift)
import           Control.Monad.Reader                (ReaderT, ask, runReaderT)
import           Control.Exception                   (throw)
import           Control.Monad                       (unless, when)
import           Control.Monad.Catch
import           Control.Monad.IO.Class              (MonadIO (..))
import           Data.Function                       (on)
import           Data.List.NonEmpty                  (NonEmpty(..))
import qualified Data.List.NonEmpty as NE
import           Data.List                           ((\\), intercalate, union)
import           System.IO.Error                     (isDoesNotExistError)
import           Text.Megaparsec                     (errorBundlePretty, parse)

-- | Monad Stack for the application
type DotEnv m a = ReaderT Config m a

-- | Loads the given list of options into the environment. Optionally
-- override existing variables with values from Dotenv files.
load ::
     MonadIO m
  => Bool -- ^ Override existing settings?
  -> [(String, String)] -- ^ List of values to be set in environment
  -> m ()
load :: forall (m :: * -> *).
MonadIO m =>
Bool -> [(String, String)] -> m ()
load Bool
override [(String, String)]
kv =
  forall r (m :: * -> *) a. ReaderT r m a -> r -> m a
runReaderT (forall (t :: * -> *) (m :: * -> *) a b.
(Foldable t, Monad m) =>
(a -> m b) -> t a -> m ()
mapM_ forall (m :: * -> *).
MonadIO m =>
(String, String) -> DotEnv m (String, String)
applySetting [(String, String)]
kv) Config
defaultConfig {configOverride :: Bool
configOverride = Bool
override}

-- | @loadFile@ parses the environment variables defined in the dotenv example
-- file and checks if they are defined in the dotenv file or in the environment.
-- It also allows to override the environment variables defined in the environment
-- with the values defined in the dotenv file.
loadFile ::
     MonadIO m
  => Config -- ^ Dotenv configuration
  -> m ()
loadFile :: forall (m :: * -> *). MonadIO m => Config -> m ()
loadFile config :: Config
config@Config {Bool
[String]
allowDuplicates :: Config -> Bool
configVerbose :: Config -> Bool
configExamplePath :: Config -> [String]
configPath :: Config -> [String]
allowDuplicates :: Bool
configVerbose :: Bool
configOverride :: Bool
configExamplePath :: [String]
configPath :: [String]
configOverride :: Config -> Bool
..} = do
  [(String, String)]
environment <- forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO IO [(String, String)]
getEnvironment

  [(String, String)]
vars <- case (forall a. [a] -> Maybe (NonEmpty a)
NE.nonEmpty [String]
configPath, forall a. [a] -> Maybe (NonEmpty a)
NE.nonEmpty [String]
configExamplePath) of
    (Maybe (NonEmpty String)
Nothing, Maybe (NonEmpty String)
_) -> forall (f :: * -> *) a. Applicative f => a -> f a
pure []
    (Just NonEmpty String
envs, Maybe (NonEmpty String)
Nothing) -> forall (t :: * -> *) a. Foldable t => t [a] -> [a]
concat forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM forall (m :: * -> *). MonadIO m => String -> m [(String, String)]
parseFile NonEmpty String
envs
    (Just NonEmpty String
envs, Just NonEmpty String
envExamples) -> do
      [(String, String)]
readVars <- forall (t :: * -> *) a. Foldable t => t [a] -> [a]
concat forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM forall (m :: * -> *). MonadIO m => String -> m [(String, String)]
parseFile NonEmpty String
envs
      [String]
neededKeys <- forall a b. (a -> b) -> [a] -> [b]
map forall a b. (a, b) -> a
fst forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (t :: * -> *) a. Foldable t => t [a] -> [a]
concat forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM forall (m :: * -> *). MonadIO m => String -> m [(String, String)]
parseFile NonEmpty String
envExamples

      let
        presentKeys :: [String]
presentKeys = (forall a. Eq a => [a] -> [a] -> [a]
union forall b c a. (b -> b -> c) -> (a -> b) -> a -> a -> c
`on` forall a b. (a -> b) -> [a] -> [b]
map forall a b. (a, b) -> a
fst) [(String, String)]
environment [(String, String)]
readVars
        missingKeys :: [String]
missingKeys = [String]
neededKeys forall a. Eq a => [a] -> [a] -> [a]
\\ [String]
presentKeys

      forall (f :: * -> *) a. Applicative f => a -> f a
pure forall a b. (a -> b) -> a -> b
$
        if forall (t :: * -> *) a. Foldable t => t a -> Bool
null [String]
missingKeys
          then [(String, String)]
readVars
          else forall a. HasCallStack => String -> a
error forall a b. (a -> b) -> a -> b
$ forall (t :: * -> *) a. Foldable t => t [a] -> [a]
concat
            [ String
"The following variables are present in "
            , String -> NonEmpty String -> String
showPaths String
"one of " NonEmpty String
envExamples
            , String
", but not set in the current environment, or "
            , String -> NonEmpty String -> String
showPaths String
"any of " NonEmpty String
envs
            , String
": "
            , forall a. [a] -> [[a]] -> [a]
intercalate String
", " [String]
missingKeys
            ]

  forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless Bool
allowDuplicates forall a b. (a -> b) -> a -> b
$ (forall (m :: * -> *). MonadIO m => [String] -> m ()
lookUpDuplicates forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a b. (a -> b) -> [a] -> [b]
map forall a b. (a, b) -> a
fst) [(String, String)]
vars
  forall r (m :: * -> *) a. ReaderT r m a -> r -> m a
runReaderT (forall (t :: * -> *) (m :: * -> *) a b.
(Foldable t, Monad m) =>
(a -> m b) -> t a -> m ()
mapM_ forall (m :: * -> *).
MonadIO m =>
(String, String) -> DotEnv m (String, String)
applySetting [(String, String)]
vars) Config
config
 where
  showPaths :: String -> NonEmpty FilePath -> String
  showPaths :: String -> NonEmpty String -> String
showPaths String
_ (String
p:|[]) = String
p
  showPaths String
prefix NonEmpty String
ps = String
prefix forall a. Semigroup a => a -> a -> a
<> forall a. [a] -> [[a]] -> [a]
intercalate String
", " (forall a. NonEmpty a -> [a]
NE.toList NonEmpty String
ps)

-- | Parses the given dotenv file and returns values /without/ adding them to
-- the environment.
parseFile ::
     MonadIO m
  => FilePath -- ^ A file containing options to read
  -> m [(String, String)] -- ^ Variables contained in the file
parseFile :: forall (m :: * -> *). MonadIO m => String -> m [(String, String)]
parseFile String
f = do
  String
contents <- forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO forall a b. (a -> b) -> a -> b
$ String -> IO String
readFile String
f
  case forall e s a.
Parsec e s a -> String -> s -> Either (ParseErrorBundle s e) a
parse Parser [ParsedVariable]
configParser String
f String
contents of
    Left ParseErrorBundle String Void
e        -> forall a. HasCallStack => String -> a
error forall a b. (a -> b) -> a -> b
$ forall s e.
(VisualStream s, TraversableStream s, ShowErrorComponent e) =>
ParseErrorBundle s e -> String
errorBundlePretty ParseErrorBundle String Void
e
    Right [ParsedVariable]
options -> forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO forall a b. (a -> b) -> a -> b
$ [ParsedVariable] -> IO [(String, String)]
interpolateParsedVariables [ParsedVariable]
options

applySetting ::
     MonadIO m
  => (String, String) -- ^ A key-value pair to set in the environment
  -> DotEnv m (String, String)
applySetting :: forall (m :: * -> *).
MonadIO m =>
(String, String) -> DotEnv m (String, String)
applySetting kv :: (String, String)
kv@(String
k, String
v) = do
  Config {Bool
[String]
allowDuplicates :: Bool
configVerbose :: Bool
configOverride :: Bool
configExamplePath :: [String]
configPath :: [String]
allowDuplicates :: Config -> Bool
configVerbose :: Config -> Bool
configExamplePath :: Config -> [String]
configPath :: Config -> [String]
configOverride :: Config -> Bool
..} <- forall r (m :: * -> *). MonadReader r m => m r
ask
  if Bool
configOverride
    then forall (m :: * -> *). MonadIO m => (String, String) -> DotEnv m ()
info (String, String)
kv forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> DotEnv m (String, String)
setEnv'
    else do
      Maybe String
res <- forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO forall a b. (a -> b) -> a -> b
$ String -> IO (Maybe String)
lookupEnv String
k
      case Maybe String
res of
        Maybe String
Nothing -> forall (m :: * -> *). MonadIO m => (String, String) -> DotEnv m ()
info (String, String)
kv forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> DotEnv m (String, String)
setEnv'
        Just String
_  -> forall (m :: * -> *) a. Monad m => a -> m a
return (String, String)
kv
  where
    setEnv' :: DotEnv m (String, String)
setEnv' = forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO forall a b. (a -> b) -> a -> b
$ String -> String -> IO ()
setEnv String
k String
v forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> forall (m :: * -> *) a. Monad m => a -> m a
return (String, String)
kv

-- | The function logs in console when a variable is loaded into the
-- environment.
info :: MonadIO m => (String, String) -> DotEnv m ()
info :: forall (m :: * -> *). MonadIO m => (String, String) -> DotEnv m ()
info (String
key, String
value) = do
  Config {Bool
[String]
allowDuplicates :: Bool
configVerbose :: Bool
configOverride :: Bool
configExamplePath :: [String]
configPath :: [String]
allowDuplicates :: Config -> Bool
configVerbose :: Config -> Bool
configExamplePath :: Config -> [String]
configPath :: Config -> [String]
configOverride :: Config -> Bool
..} <- forall r (m :: * -> *). MonadReader r m => m r
ask
  forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when Bool
configVerbose forall a b. (a -> b) -> a -> b
$
    forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO forall a b. (a -> b) -> a -> b
$
    String -> IO ()
putStrLn forall a b. (a -> b) -> a -> b
$ String
"[INFO]: Load env '" forall a. [a] -> [a] -> [a]
++ String
key forall a. [a] -> [a] -> [a]
++ String
"' with value '" forall a. [a] -> [a] -> [a]
++ String
value forall a. [a] -> [a] -> [a]
++ String
"'"

-- | The helper allows to avoid exceptions in the case of missing files and
-- perform some action instead.
--
-- @since 0.3.1.0
onMissingFile ::
     MonadCatch m
  => m a -- ^ Action to perform that may fail because of missing file
  -> m a -- ^ Action to perform if file is indeed missing
  -> m a
onMissingFile :: forall (m :: * -> *) a. MonadCatch m => m a -> m a -> m a
onMissingFile m a
f m a
h = forall (m :: * -> *) e a.
(MonadCatch m, Exception e) =>
(e -> Bool) -> m a -> (e -> m a) -> m a
catchIf IOError -> Bool
isDoesNotExistError m a
f (forall a b. a -> b -> a
const m a
h)

-- | The helper throws an exception if the allow duplicate is set to False.
forbidDuplicates :: MonadIO m => String -> m ()
forbidDuplicates :: forall (m :: * -> *). MonadIO m => String -> m ()
forbidDuplicates String
key =
  forall a e. Exception e => e -> a
throw forall a b. (a -> b) -> a -> b
$
  String -> IOError
userError forall a b. (a -> b) -> a -> b
$
  String
"[ERROR]: Env '" forall a. [a] -> [a] -> [a]
++
  String
key forall a. [a] -> [a] -> [a]
++
  String
"' is duplicated in a dotenv file. Please, fix that (or remove --no-dups)."

lookUpDuplicates :: MonadIO m => [String] -> m ()
lookUpDuplicates :: forall (m :: * -> *). MonadIO m => [String] -> m ()
lookUpDuplicates [] = forall (m :: * -> *) a. Monad m => a -> m a
return ()
lookUpDuplicates [String
_] = forall (m :: * -> *) a. Monad m => a -> m a
return ()
lookUpDuplicates (String
x:[String]
xs) =
  if String
x forall (t :: * -> *) a. (Foldable t, Eq a) => a -> t a -> Bool
`elem` [String]
xs
    then forall (m :: * -> *). MonadIO m => String -> m ()
forbidDuplicates String
x
    else forall (m :: * -> *). MonadIO m => [String] -> m ()
lookUpDuplicates [String]
xs